Friday, April 25th, 2014 at 12:05am

Q: My 10-year-old cat has had eye drainage for quite a while. My veterinarian referred us to an ophthalmologist who thought it might be an allergy. Prescription food z/d did not help. He also has recurring sores above both eyes that he scratches open.

Dr. Nichol: I’m sorry about your cat’s discharge and the wounds on his face. Having ruled out eye disease, the ophthalmologist may be right about an allergy. Airborne pollens and other particles irritating the tissues beneath your boy’s eyelids could certainly be responsible. Hair loss and chronic wounds on the forehead are a common result of repeated scratching and rubbing. It’s possible that skin disease is the underlying cause of this whole debacle.

The next move should be a thorough skin exam. That means scrapings to check for mange, an impression smear to hunt for bacterial and yeast organisms, and a fungal culture to ferret out ringworm. Scabies, demodex and head mange mites can be crafty little devils, evading even the most exhaustive search. If your veterinarian still regards these burrowing insects as parasites of interest, it would be wise to treat for them anyway with oral iverrnectin or topical selamectin. Antibiotics to control the smoldering skin infection of your cat’s long-suffering face will be important from the get-go.

Unraveling diagnostic riddles can become a process of elimination. If a careful workup plus mange treatment fails to reveal the answer, your boy may simply need a treatment trial for airborne allergies. An antihistamine like Benadryl, along with fish oil, could finally give him relief. More potent prescription anti-itch medications like cyclosporine are also available.

If all else fails, it may be best for your cat’s skin to be evaluated by a veterinary dermatologist. These specialists tackle the really tough cases. Skin testing is sometimes necessary to determine the exact cause of allergies so that a series of desensitization injections can be custom-tailored for the individual.

It might seem easier and cheaper to start at the end of the process but this little guy has been miserable for a long time. There is no substitute for an accurate diagnosis when the goal is to reach the greatest improvement in quality of life.

Dr. Jeff Nichol treats behavior disorders at the Veterinary Specialty Centers in Albuquerque and Santa Fe (505-792-5131). He cares for the medical needs of pets at the Petroglyph Animal Hospital in Albuquerque (898-8874). Question? Post it on facebook.com/drjeffnichol or by mail to 4000 Montgomery NE, Albuquerque, NM 87109. Unpublished questions may not be answered individually.